In August 2022, Pakistan experienced an unprecedented precipitation event that caused significant damage. Analysis of the observations reveals that this extreme rainfall is primarily driven by anomalous atmospheric zonal advection, resulting in an anomalous water vapor concentration in Pakistan. The climatological meridional advection also contributes to this flooding. Anomalous easterly winds and low-level vertical convection combine to be critical factors contributing to the moisture concentration over the country. Further investigation identifies the air-sea interaction over the tropical Indian Ocean and abnormal warming over the Arabian Sea are crucial factors influencing this extreme flooding event. The concurrent occurrence of a negative Indian Ocean Dipole event and the warming sea surface temperature anomalies in the northern Arabian Sea intensifies the easterly winds over Pakistan, helping to transfer the anomalous water vapor from the remote region into Pakistan, ultimately contributing to the extreme flooding in 2022.

中文翻译：

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2022年夏季热带海面温度对巴基斯坦极端降水的影响

2022年8月，巴基斯坦经历了前所未有的降水事件，造成了重大损失。对观测结果的分析表明，这次极端降雨主要是由异常的大气纬向平流驱动的，导致巴基斯坦水汽浓度异常。气候经向平流也导致了这次洪水。异常东风和低层垂直对流共同是导致全国湿度集中的关键因素。进一步调查发现，热带印度洋上空的海气相互作用和阿拉伯海的异常变暖是影响这次极端洪水事件的关键因素。印度洋负偶极子事件和阿拉伯海北部海温异常变暖同时发生，加剧了巴基斯坦上空的东风，帮助将偏远地区的异常水汽输送到巴基斯坦，最终导致了巴基斯坦的极端洪涝灾害。 2022 年。